Answer:
Option D. 5.45 Ω
Step-by-step explanation:
From the question given above, the following data were obtained:
Resistance 1 (R₁) = 10 Ω
Resistance 2 (R₂) = 20 Ω
Resistance 3 (R₃) = 30 Ω
Voltage (V) = 120 V
Equivalent resistance (R) =?
The equivalent resistance can be obtained as follow:
1/R = 1/R₁ + 1/R₂ + 1/R₃
1/R = 1/10 + 1/20 + 1/30
Find the least common multiple (lcm) of 10, 20 and 30. The result is 60
Divide 60 by each of the denominators and multiply by their numerators respectively. We have:
1/R = (6 + 3 + 2)/60
1/R = 11/60
Invert
R = 60/11
R = 5.45 Ω
Thus, the equivalent resistance in the circuit is 5.45 Ω